The present invention relates to wind energy converters and, more specifically, to a greatly simplified wind driven converter for use with an electrical generator of conventional construction. The present invention is more particularly characterized by a low initial cost and good efficiency over a greater range of wind velocity. The device is also distinguished in the simplicity of its structure and its reliability over an extended interval before requiring servicing.
With the increasingly stringent regulations governing the use of fossil fuels to generate power, alternative sources of electrical power such as solar and wind power are becoming increasingly economical and attractive to the marketplace. In addition, in many remote areas in this and other countries, alternative sources of electrical power are becoming a necessity with increasing population density in such remote locations. However, as is frequently the case, the more remote the location, the more destitute are the inhabitants likely to be thus making an investment in alternative power generation on a scale so as to make it profitable or sufficient to meet the anticipated needs very improbable.
The prior art has proposed a large number of different structures for making use of a wind energy to generate electrical power. The structures have generally been complicated to install and difficult and expensive to maintain over long periods of time in view of the large number of moving parts that are required. In other arrangements, efficient operation could only be achieved where the velocity of the wind current averaged at a relatively large magnitude. This made the structures useful in only a relatively few locations. Typically, the designs of the prior art involved the construction of a windmill mounted at a selected height above the ground or structure on which it is supported. The rotary output of the windmill is usually connected to a crankshaft adapted to rotate a conductive coil or primary windings in a magnetic field in order to generate current in the secondary windings of the generator. Windmill structures typically are balanced annulus shapes thereby offering little if any mechanical advantage to overcome the weight of the primary windings of the generator together with the weight of the connecting linkages. As a consequence, it has frequently been necessary to construct the windmill with relatively large surface area vanes. As a consequence, the expense of construction has often been adversely affected.
The structure of the present invention greatly simplifies the operation of the surfaces interacting with the wind current thereby substantially reducing the cost of construction and greatly simplifying the maintenance required for the apparatus. In one embodiment, a post is mounted on a table about which the post is free to rotate to enable the apparatus to align itself favorably with the prevailing wind direction. The post supports adjacent one end a pivot arm pivotally mounted adjacent one end of the pivot arm. The remote end of the pivot arm supports at least one and preferably a pair of airfoil shaped vanes, which are mounted on a pin or rod extending through the pivot arm so that the pin will be at right angles or perpendicular to a plane in which the pivot arm will move in operation. Preferably, the vanes are eccentrically mounted on the pin or rod in a manner to favor movement into the wind.
The opposite end of the pivot arm is connected through a linkage to an input shaft of an electrical generator of conventional construction. In addition, motion limiting structure is carried by the pivot arm to limit the degree of pivoting that the vane or vanes are permitted. This will assure that the vanes assume an angular position relative to the wind flow that will cause the pivot arm to move from one limit position through an arc to an opposite limit position whereupon the position of the vanes changes to move the pivot arm back to its original position to repeat the cycle. With this arrangement, reliable operation over an extended period will be far less expensively achieved compared with the windmill structures common to the prior art.
The forgoing and other advantages will become apparent as consideration is given to the following description taken in conjunction with the accompanying drawings, in which: